In a projectile loom, the filling or weft yarns are drawn across the web of the cloth by a shuttle, a flat metal canister with a rounded nose. The shuttle travels across the web at a high velocity, and is stopped in a very short distance. At the end of travel, the shuttle passes into a gap between an upper and lower brake pad, set to engage the oncoming shuttle and stop the motion of the shuttle.
The stopping position of the shuttle is indefinite, due to such variables as thickness, weight, and lubricity of each individual shuttle, and also due to wear on the brake pads. Accordingly, the brakes are intentionally set to stop the shuttle a short distance beyond the predetermined point at which the yarn is automatically released from the shuttle, and the shuttle thereafter is transferred to a conveyor chain for return to the opposite side of the loom.
When the shuttle enters the braking system, the shuttle returner is at rest a short linear distance beyond the area in which the shuttle is stopped by the brakes. The shuttle returner immediately advances to engage the nose of the braked shuttle and push the shuttle back to the exact position for releasing the filler yarn to the selvage tucking system. The shuttle is subsequently transferred to the conveyor chain for return to the opposite side of the loom.
In actual operation of a projectile loom, the shuttles often overrun the braking system and strike the shuttle returner so that both the nose of the shuttle and the receiving surface of the returner become battered to the point that either or both components must eventually be replaced. This replacement of the shuttle returner is costly not only in the material and labor expense for replacement, but also in the downtime incurred while the loom is withdrawn from operatin to replace the broken shuttles or shuttle returner.
Prior art efforts to alleviate the cost of repair and down time associated with damaged shuttles and shuttle returners usually have involved making those parts more durable, or refining the shuttle braking system to stop the entering shuttle with greater accuracy and reliability. Both approaches to improving the lifetime of shuttles and shuttle returners have, at best, produced marginal gains in the lifetime of the parts involved. Another approach to solving the problem is shown in U.S. Pat. No. 4,415,010 to Schmitz, which proposes an elastically yielding and damping body disposed to absorb impact forces. This latter proposal has not been adopted in commercial practice, however, and does not appear as a significant answer to the problem confronted by the art.